The present invention relates to a radiant source scan channel of an automatic scan type radiation detecting system for detecting large objects, and more particularly, to a double-radiant-source scan channel structure, which belongs to the technical field of radiation detection.
Container freight/vehicle detecting system is the major detecting device that the customs needs. So far, customs in most of the countries mainly adopts a method of opening the container or a method of single-radiant-source radiation imaging in the detection of the container trucks passing through the customs. The detection method of opening the container and tearing open the freight needs a long time, with a low detection amount per day, and has a high detection cost, which seriously affects the speed of the container trucks passing through the customs. In order to solve this problem, a detecting system using single-radiant-source radiation imaging was developed. The detecting system for detecting large scale container freight/vehicle using an accelerator or Co 60 as the radiant source have been developed, such as the detecting systems for detecting large scale container freight/vehicle manufactured by Heimann in Germany and Aerospace in British. The detecting system is disposed in a detecting channel capable of shielding rays, and comprises an immovable radiant source capable of generating high energy X-rays and a detector array capable of receiving X-ray that pass through the container. The vehicle loaded with containers is dragged to pass through the detecting channel using a special dragging device. When the containers move through the X-ray, the X-ray that transmit through the containers are incident to the detector, which reflects the density distribution of the contained objects in accordance with the intensity of the X-ray, and converts the intensity of the ray into image gradations so as to obtain the scenograph of the objects that are in the container. Although the aforesaid system has solved the problem of obtaining the scenograph of the objects contained in the container without opening the container and thus raises the detecting speed, it has the defects as a complex structure, a large area coverage, inconvenient installation and imperfect image effect for detection.